Process of making piston rings



Jan. 13, 1931. J. WILLIAMS ET AL 7 1,788,697

I PROCESS OF MAKING- PISTON RINGS Original Filed March 20, 1926 2 Sheets-Sheet l Jan. 13, 1931.

Original Filed March 20,- 1926 2 Sheets-Sheet 2 Fatented den, E3, 1233 H LIAMS, Q1? PHILELJPHIA, PENNSYLVANIA ERQCWS 01F MAKING PISTON RINGS Original application filed march 20, 1926, Serial No.

96,266. Divided and this application filed. May, 23, r

1928. Serial No. 276,992.

This invention relates to an improved process of making piston rings, beinga division of my co-pending application for piston ring and process of making same,

5 filed March 20, 1926, Serial No. 96,266, Pat.

No. 1,639,608, patented Oct. 30, 1928.

The invention seeks, among other objects, to provide an. improved process of making piston rings of cast, iron and wherein the ring will be provided with waves or corrugations.

Other objects of the invention not specificall mentioned in the foregoing will appear during the course of the following descripistion.

In the accompanying drawings,

Figure 1 is a perspective view of the blank from which the improved ring is formed,

Figure 2 is an elevation showing the step of die pressing the blank to produce waves or corrugations therein,

Figure 3 is a perspective view showing the corrugated ring as it is placed on the market and delivered to the user,

Figure 4 is an elevation showing the step of snapping the rin so that the ring may be flexed and app ied in a piston ring groove,

Figure 5 is a perspective view showing the rin after being snapped,

igure 6 is a view partly in elevation and partly in section and showing the tensioning ring in position in a piston ring groove beneath a conventional piston ring.

In Figure 1 of the drawings, I have shown a flat, endless annular blank 10 of cast iron which may be of any chosen thickness. The blank is produced from a cylindrical pot- 40 casted shell, the shell being cut to form the blank, and, preferably, each blank is of uniform thickness throughout its circumference. The pot casting of the shell mentioned may be accomplished in accordance with approved methods, as may also the cutting of the shell to produce the blank and since, as shown in Figure 6, the ring evolved from the blank is of less diameter than the piston upon which the ring is used, it is unnecessary to finish or smooth the inner and outer edges of the blank. However, the side faces of the blank are preferably smoothed in approved manner.

Having formed the blank 10, said blank is then heated to an annealing temperature, say about 1500 or 1700 Fahrenheit, when, as shown in Figure 2, the blank is, while at said temperature, pressed between the corrugated male and female dies 11 and 12 of a die press and thus shaped to produce a circumferentially corrugated ring. If desired, the dies 11 and 12 may be water cooled and the ring is held between'the dies until said ring has cooled sufliciently to retain its corrugated shape when the ring is removed, and, although not necessary, the ring may, immediately upon being removed from between the dies, be immersed in a quenching bath.- Thus, as shown in Figure 3, an endless corrugated ring 13 is formed and, of course, the ring may be provided with any approved number of corrugations or oppositely bowed portions. 7

In practice, the corru ated' ring, as shown in Figure 3, is shippe to the distributor, dealer, or user, as the case may be, in endless form, and in order to apply the ring to a piston it accordingly becomes necessary to snap the ring at a point in its periphery so that the ring may be flexed about the piston and engaged in the desired ring groove. As will be perceived, the ring, therefore, remains .a continuously integral structure until such time as the ring is actually installed for use and it has been found that, as compared with a split ring, the endless ring is much less likely to become distorted or broken in handling. In Figure 4, I have shown the preferred manner in which the endless ringis snapped at a point in its periphery. As illustrated, a portion of the ring is grasped between the thumbs and forefingers of the hands and, as will be observed, the forefingers are disposed close together at one side of the ring. Accordingly, by flexing with the thumbs the portion of the ring intervening there-between, the ring may be snapped against the fulcrum provided by the forefingers. In

, cooperate with the cylinder wall for presnapping the ring in the manner indicated,

the ring will be unlikely to break at more than onepoint while a clean break will be produced. Thus, as shown in Figure 5, the ring is split ready to be applied to an engine piston and it should be observed that by forming the ring from a cylindrical pot casting, the wall of which is of uniform thickness, as in the present instance, the metal of the ring is of the same density and uniform physical properties throughout the entire circumference of the ring and, accordingly, the ring may be manually snapped at any one point in its circumference as easily as at any other point.

In Figure 6 of the drawings, I have shown the ring installed. A portion of the piston is conventionally illustrated at 14, one of the ring grooves of the piston at 15, and a conventional split piston ring at 16. By flexing the end portions of the ring 13 with respect to each other, said ring may be readily applied about the piston to enter the ring groove and, in the present instance, I have shown said ring disposed beneath the piston ring 16. The ring 13 is thus compressed or flattened somewhat between the piston ring and the bottom wall of the ring groove so that the ring 13 is thus held under tension for pressing-the piston ring tightly against the top wall of the groove. Leakageof compression past the piston ring will thus be reduced to a minimum while, also, movement of the piston ring within the ring groove in a direction axially of the piston will be prevented so that oil pumping will likewise be reduced to a minimum. As

will be a preciated, the ring 13 may be employed a ove a piston ring for holding the piston ring tightly against the bottom wall of the ring groove, or may be employed between a air of piston rings for holding the rings of the pair of rings tightly against the top and bottom walls of the groove. As will be understood in view of the foregoing, the ring 13 will, in each instance, be held under tension so that independent movement of the piston ring or rings will -be prevented. Furthermore, it is to be particularly noted that since the ring 13 is of cast iron, said ring will effectually withstand any maximum operating temperature to which an engine may be subjected and will accordingly permanently retain its resiliency so that, in contrast with conventional steel spring rings, looseness of the usual piston ring will not develop after a short period of service of the cast iron ring. Also, it is to be noted that the ring 13 will permanently exert a frictional tension on the piston ring for preventing sidewise movement of the piston ring relative to the piston so that the piston ring will be supported to venting slapping of the piston.

JOHN WILLIAMS. L 8. JUDSON WILLIAMS. 1,. 8.]

tures. 

